Unexplored Links: Climate Change and Environmental Contaminants

By Roberta Attanasio, IEAM Blog Editor

Greenland ice melt figure

Rapid surface ice melt in Greenland (July 2012). Credit: NASA Goddard Space Flight Center, CC BY 2.0

Climate change is happening here and now, and the rate of change is also speeding up, as demonstrated by a recent study. The most dramatic effects are clearly visible all around us—shifting precipitation patterns, sea level rise, ocean acidification, shrinking Arctic sea ice, melting of the Greenland and Antarctica ice sheets, and amplified occurrence of wildfires, floods, heat waves, and droughts. Climate change is also a threat multiplier—the environmental fallout it causes can exacerbate political instability in the world’s most dangerous regions and increase the chances of armed conflict. In addition to these conspicuously damaging effects, there are some others that are causing alarm, although not discussed as often and not as clearly discernible at this time: climate change may alter the release, dispersal, and toxic effect of chemicals in the environment, potentially resulting in dangerous levels of human exposure and deleterious consequences for ecosystems.

Beijing Olympic stadium

Beijing Olympic stadium shrouded in smog. Credit: rytc, CC BY-NC-ND 2.0

One “climate hypothesis” provides an example of how climate change interacts with environmental pollutants. Formulated to explain how climate change could foil China’s smog-fighting efforts, the reasoning goes, “As the earth warms, the high-pressure system of cold air known as the Siberian High that influences many places, including China, weakens. That means there is less wind to blow away the smog and stagnant air where pollutants accumulate and interact. That leads to increased haze, cutting sunlight’s access to the ground, leaving it cooler. The effect reduces the heat that produces convectional rainfall that could clear the air.” Such interactions have been defined “not so much a vicious circle as a vicious pretzel, or even knot.”

So why use a “hypothesis” as an example of the effects that climate change could have on the environmental impacts of toxic chemicals? Simply said, not enough is known about these effects. Despite significant concerns raised in the past few years, research in the area is lacking.

China smog satellite photo

Smog over eastern China. Credit: NASA Goddard Space Flight Center, CC BY 2.0

Back in 2010, Rick Wenning (Editor-in-Chief, Integrated Environmental Assessment and Management) and his collaborators issued a “call for research.” Together, they challenged environmental chemists, toxicologists, and risk assessors belonging to the Society of Environmental Toxicology and Chemistry (SETAC) to work together to understand how global climate change influences the mechanisms and ramifications of contaminants on humans and the environment.

However, despite the initial call, not much progress has been made. A follow-up article published at the end of 2014, “Global climate change and contaminants, a call to arms not yet heard”, reveals that there continues to be a lack of studies seeking to understand the interactions between climate change, contaminants, and environmental risk. The article highlights five points of consensus that represent a call to arms for research to advance our understanding of environmental chemistry and toxicology in the context of global climate change.

Lead author Wayne Landis at Western Washington University explained in a recent interview released to the IEAM blog that global climate change and human actions interact to control the fate and distribution of chemicals in the environment—the recognition of such an interaction is at the basis of the first point of consensus. What about the other four points?

Landis goes on to explain that climate change affects the toxicity of chemicals, and that the toxicity of chemicals affects the ability of organisms to adapt to climate change (point 2). In addition, the rate of effects on ecosystems is variable—some populations are more vulnerable, whereas others may show little immediate change (point 3). The fourth point of consensus states that it is necessary to incorporate the effects of climate change on human health and in ecological risk assessments, in order to correctly predict the risks posed by chemicals and other stressors. Finally, the fifth point of consensus recognizes that the reference state, or baseline, for estimating injury to natural resources will be shifting as a consequence of climate change.

Flooded LaSalle IL wastewater plant

2008 flood at the LaSalle wastewater plant (LaSalle, Illinois, US). Credit: Pam Broviak, CC BY-SA 2.0

The five points of consensus clearly highlight the complexity of the interactions between climate change and environmental pollutants—complexity that was first delineated years ago. Indeed, a 2008 report released by the Intergovernmental Forum on Chemical Safety states: “The physical changes in temperature, wind, and rainfall caused by climate change will affect the distribution and breakdown of chemicals in complex ways. The effect on human exposure will vary widely according to the properties of specific chemicals and chemical combinations, soil and water conditions, wind patterns, topography, land use, level of development, and human population characteristics.”

So, why is it taking so long for researchers to fully realize that toxic effects are influenced by climate change, and that climate change is critical to the future of toxicology? A lack of interdisciplinary collaboration may be to blame. According to Landis: “Climate change research has been dominated by climatologists, as it should have been. Ecologists often have little background on the effects of manufactured chemicals. Toxicologists work at the molecular to ecological scales, and have little interaction with climate scientists. Without interaction, cross-fertilization among different disciplines cannot occur.”

Although the multiplicity of factors that play a role in the interaction between climate change and environmental pollutants, and the cross-fertilization of disciplines required to understand these interactions may represent a challenge for the development of viable research plans, the 5 points of consensus provide a framework for action. As Landis points out, the merging of climate change and toxicology requires a paradigm shift. All together, scientists need to recognize that chemical contamination is widespread, and that climate is a toxicological driver. The call to arms cannot be left unanswered.

5 thoughts on “Unexplored Links: Climate Change and Environmental Contaminants

  1. Ray Kinney

    Yes, and chronic low dose accumulative effects add up to health limiting anthropogenic influence on pathogenicity for humans and wildlife. Most of the public health paradigm focuses on symptom abatement, while largely ignoring pointedly investigative causation determination necessary for public health to recognize the role climate change plays in potentiating physiologic degradation. Media focuses on the ‘news-worthy ‘belly-up’ acute toxic harm to the few, yet does not usually try to adequately educate about chronic low dose multi-toxicant exposure adverse effects to the many. The phrase “The solution to pollution is dilution” is rapidly becoming a very inappropriate phrase to describe reality on this small blue orb.

  2. Wayne Landis

    Of course I might be biased but I really like the summary of the issues covered in the Blog. The papers that appeared in Environmental Toxicology and Chemistry should be considered the beginning of the conversation and a lot of other research needs to be done.

  3. Fred Pinkney

    One example of a followup is a paper now in early view at IEAM, Pinkney, A.E. C.T. Driscoll, D.C. Evers, M.J. Hooper, J. Horan, J.W. Jones, R.S. Lazarus, H.G. Marshall, A. Milliken, B.A. Rattner, J. Schmerfeld, and D.W. Sparling. (in press). Interactive effects of climate change with nutrients, mercury, and freshwater acidification on key taxa in the North Atlantic Landscape Conservation Cooperative region. Integrated Environmental Assessment and Management DOI 10.1002/ieam.1612. Our goal was to take the findings of the SETAC workshop and apply the approach to focus on selected issues of importance in the Northeast U.S. and Canada. We summarized what is known and identify key research needs. Our hope is that the several public private partnerships such as the Landscape Conservation Cooperatives and Climate Science Centers will consider funding research on climate-contaminant and climate-nutrient interactions in the future.

  4. Ray Kinney

    Atmospheric contaminants volitalized from lower latitude chemical applications can travel far into the north latitudes where they can accumulate in cold storage until massive melting of snow and ice liberates the accumulations quickly. This can produce much higher doses than the original atmospheric concentrations were. This is reflected in tissue sampling of north latitude organisms including human breastmilk.

  5. Ray Kinney

    Any call to arms needs funding. The 1% is invested in the status quo. Enough funds will not flow unless the 1% wants them to flow. They will not allow enough good science to adequately demonstrate the climate change/toxicology paradigm until they personally, and collectively, really fear for themselves and their families. With the resources they have as a cushion, that may take far too long. How can we be effective given this disadvantage and next to no funding? There must be about 1% of that 1% that are predisposed to understand this grave problem for funding our hope for being in time with the science. How can we best find and approach this rare subset?
    The vast funds at the disposal of the 1% insulate them with a false sense of security, they cannot admit their vulnerability, and likely they would have more trouble controlling one of their own… but would try. Finding 1% of 1% is likely to be key. Who will do that, and how? For five points of consensus to produce action, it takes more than five points of consensus. IMHO


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